Baseline urinary phytoestrogen levels and the natural history of untreated, localised prostate cancer in a British population.
OBJECTIVE
To determine whether urinary concentrations of phytoestrogens are associated with the rate of disease progression in men with untreated, localised prostate cancer.


METHODS
Patients with untreated, localised prostatic adenocarcinoma on a prospective clinical study of active surveillance had urine samples collected at baseline. Patients underwent monitoring with serial PSA levels and repeat octant prostate biopsies. Disease progression was defined as either adverse histology on repeat biopsy (primary Gleason grade >or= 4, or >50% positive cores) or radical treatment for PSA velocity >1 ng/mL/year. Time to disease progression was analysed with respect to baseline urinary levels of genistein, enterolactone, daidzein and equol, assayed using liquid chromatography/tandem mass spectrometry.


RESULTS
191 patients were evaluable, with a median follow-up of 2.5 years. 71 patients experienced disease progression. No significant association was seen between time to disease progression and baseline urinary levels of daidzein (p=0.85), genistein (p=0.81), enterolactone (p=0.085) or equol (p=0.33). No significant association was seen between adverse histology on repeat biopsy and urinary levels of either daidzein (p=0.85), genistein (p=0.58), enterolactone (p=0.88) or equol (p=0.71). There was no significant correlation between PSA velocity and urinary levels of daidzein (p=0.90), genistein (p=0.98), enterolactone (p=0.10) or equol (p=0.60).


CONCLUSIONS
These data do not support the hypothesis that phytoestrogens prevent disease progression in men with localised prostate cancer.
Venkitaraman
R
R
Academic Unit of Radiotherapy and Oncology, Institute of Cancer Research, Sutton, Surrey, UK.
Thomas
K
K
Grace
P
P
Dearnaley
D
D
Horwich
A
A
Huddart
R
R
Parker
C C
CC
D000368:Aged; D001706:Biopsy; D019587:Dietary Supplements; D018450:Disease Progression; D006801:Humans; D008297:Male; D008875:Middle Aged; D048789:Phytoestrogens / Q000378:metabolism* / Q000652:urine*; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000096:biosynthesis; D011471:Prostatic Neoplasms / Q000175:diagnosis / Q000453:epidemiology / Q000652:urine*; D016896:Treatment Outcome; D006113:United Kingdom
D048789:Phytoestrogens; D017430:Prostate-Specific Antigen